Caustic Subtances
by noenigma
Summary: SG-1 in another mission gone bad...set after Beneath the Surface in Season 4.


_This one is set sometime after Beneath the Surface in Season 4._

Disclaimer: Purely for fan purposes; no copyright infringement intended.

Stepping through the Gate never gets old, Carter thought as she stepped out of the event horizon and onto a planet half a galaxy away from home. Often, the vast differences between worlds weren't immediately apparent. This time, however, there was no escaping the fact they weren't in Kansas. The sky had a greener tinge to its blue than any sky ever seen on Earth. Its few, wispy clouds were the shade of new leaves in spring.

Even as she assessed the area for trouble, her mind ran through various possibilities to explain the phenomenon. Something in the atmosphere she concluded. She began to speculate on the best way to test that hypothesis even as she conferred with her teammates on the wisest choice of direction they should take and checked the equipment to make sure they really had brought everything they needed.

Her CO caught her eye and laughed. "Can't stand it, can you, Major?" he asked.

"Sir?"

"The sky...you can't stand not knowing what's causing that can you?"

She turned back to the equipment without answering.

"Come on, admit it...bet you've got a theory or two you want to check out if there's time."

"Well, you have to admit it's not something we've seen before, Sir."

"Aha! So I am right!" The colonel gave her a companionable pat on the back and headed off 'that a way'. Smiling, the team moved off towards their mission objective after him.

The MALP had sent back just enough info to make the scientists back home think there was a possibility tritanium deposits were present on the planet. To O'Neill's disgust, SG-1 had been sent to check it out. He'd found few missions were as brain-numbingly boring as those that had all the scientists back home drooling with excitement. He cast an eye on his own pet scientist. She didn't seem nearly as excited to assay for tritanium as she was to take a crack at explaining that green sky. He sighed. They'd either have to double time on the geographical survey or extend the mission. There wasn't any way they'd be leaving the planet without gathering data and making observations on that sky-at least not without carrying Carter out feet first.

Daniel Jackson found the planet, like all those they'd encountered with skies of distinctly unearthly hues, somewhat disorienting. Give him the blue skies of home any day, he thought morosely as they trudged on.

Teal'c also found something about the place disquieting. The decidedly green cast of the sun bathed everything in its slightly disturbing light making the browns of tree trunks and paths look off. And the greens of the grass and leaves were garish and harsh. The longer they walked the more uncomfortable he felt. This planet was so alien it made his adopted home on Earth seem as familiar as the worlds of his younger years.

"I do not like this world, O'Neill," he stated.

"That would make two of us," Daniel added in agreement.

O'Neill stopped immediately. "What is it?" he questioned them intently. Teal'c was aware the human had learned to trust his heightened senses and years of experience. If he could give substance to his unease, O'Neill would not discount it. Unfortunately, he could not.

"I just do not like it," he said, feeling foolish.

"But, you don't see any reason to scrap the mission?" O'Neill asked him.

"No," he answered reluctantly.

O'Neill glanced at Carter. She'd taken advantage of the little bit of downtime to pull a few small instruments from her backpack. Now she was too engrossed in what they were showing to notice his look. With a shrug, he resumed walking and the rest followed along.

"Well, it is different all right," he said. "Even smells a bit off, don't you think? Kind of sweet."

"I have not noticed a smell," Teal'c answered.

"I have," Daniel said. "Like walking through a field of alfalfa on a too hot day...it's making me feel a bit sick actually."

"How about you, Carter?" O'Neill turned to the major. She shrugged her shoulders.

"Smells a bit different from Earth, but not much. I like it here," she added. The guys all gave her a "you would" sort of look which she answered with her typically bright smile. "I'm hoping the color difference shows up well on the camera. It wasn't pronounced enough to show on the MALP's footage."

"I can't imagine this not showing up," Daniel said. "It's quite a bit darker now than it was when we started."

Sam turned from her instruments to see Daniel was right. While the sky itself was still more blue than green, and the sun more yellow than otherwise, the clouds had definitely changed into a deep green while they had been walking. They were no longer wisps of spring green, but substantial formations resembling large, dark watermelon in the sky. She frowned down at her instruments and then said, "Sir."

From the tone of her voice the colonel knew the mission had just changed. "Major?" he asked. "What is it?"

"I don't know, Sir. The instruments aren't showing anything, but..."

"Maybe it's perfectly normal here. We've been walking a couple of hours...maybe as the day progresses the color changes?"

"I can't say, Sir," she said.

"Turn back or complete the mission?" he demanded of her.

She shrugged her inability to give him a satisfactory answer.

"Maybe it's a storm," Daniel offered.

"Perhaps," said Teal'c.

Carter jumped in with the kind of statement he hated to hear, "If it rains, Sir, we could be in trouble."

"Carter?"

"Well, there are several substances we know about, and probably plenty more we don't, that could be present in the atmosphere to cause this color change." She looked at him expectantly. She had high expectations of him, but, as usual, he was clueless.

Not seeing any lightbulbs going off, she prompted helpfully, "Think acid rain, Sir."

"I'd really rather not," he told her dryly. He took a quick look to confirm what he already knew: the planet was lush with no signs of corrosive wear. "Wouldn't we see signs of that?"

"Maybe not if it was normal to the planet," Daniel mused, and Carter nodded her agreement.

"If these plants developed here they might be adapted to withstand or even flourish in it," she added.

"There're a whole lot of 'maybes' here, folks. I don't like it," O'Neill said, scowling. His team waited silently for him to get over his dislike of the situation and come to a decision. He pursed his lips and nodded his head as he made up his mind. "We'll go on, but stick to the trees," he decided. "If it starts raining we'll hope they'll provide enough shelter to protect us if there is a problem. The folks back home were too excited about this find to let this mission drop. If we back out, they'll just send someone else. And," he continued, "those clouds are building fast. We've come quite a distance. If it is a storm, I don't think we can make it back to the Gate." Having blessed them with more explanation as to his decision than usual, he strode off without waiting for further discussion. Once again, they followed him.

A sudden, strong gust of wind whipped about them; taking with it Daniel's hat from off his head and bringing with it the first drops of rain. Daniel instinctively gave chase just as the rain changed from a gentle sprinkling to a violent downpour. A rather peeved colonel jerked him back under the canopy of the leaves just as he managed to grasp his hat.

"Daniel! What were you thinking? You know-" O'Neill never finished the chewing out. Daniel dropped his sodden hat like a hot potato and with a small exclamation grabbed his hand to his chest in obvious pain. For a brief second, the others looked in horror at his smoking hat slowly disintegrating on the forest floor. With a stifled cry of disgust, O'Neill kicked what was left of it away from them.

Then they were on Daniel, pulling off his field jacket splattered with raindrops and flinging it away. With shaking hands, Sam poured her canteen water over his burnt hand and applied the burn salve they carried in their first aid kits. Jack pawed through his pack and kit to find the painkillers and antibiotics and thrust them into Daniel's other hand. Fighting back tears of pain, he took them meekly.

"Sorry, Jack" he muttered and received a rough grunt back in reply.

Sam picked up where he left off, "I'm sorry, Sir. I should have-"

"What, Carter? Left your curiosity back home with your cat? Forget it. I knew the risks...I made the call, I get the guilt. That's how it works. Just tell me where we can go if that wind kicks up again and how long before whatever that is falling from the sky eats through these leaves and we all go up in smoke?"

Sam looked around her. The wind had died as quickly as it had come up, or, she realized with a shudder, they all would have been soaked and in far worse shape than Daniel. The leaves over their heads were somehow withstanding the corrosiveness of the rain. They formed a canopy of protection extending several feet out and funneling the moisture away from the area directly under the trees. The rain ran off the sides of the canopy in a steady sheet, splashing to the ground a safe distance from SG-1. For now the soil thirstily drank the moisture up, but once the ground became saturated...she didn't want to know how long their combat boots would protect them from its effects.

"Major?" the colonel called her back, and she turned her focus to the here and now.

"Tenting, Sir. We can secure it around us to block any wind if it picks up again...and we should get it overhead, as well, in case the rain starts filtering through the leaves."

"Right," he answered already digging into packs for what they would need. They bickered over the question of just how far it was safe to set their perimeter... they couldn't risk setting it too close to the corrosive brew splattering all around them, but if the storm should last hours or days they'd need every inch they could eek out. Compromising in the end, they went about the awkward business of making their makeshift shelter.

Daniel was no help. The pain had receded to just a dull ache, but the meds had left him groggy and off-balance. He was grateful when Jack gave the word, and he was allowed to lower himself to the ground and close his eyes against the assault of the day. Jack tossed a pack at him for a pillow, and he thankfully drifted to sleep.

The sound of rain hitting the canvas roof woke him later, and it took him a moment to fathom why that sound had sent his heart rate skyrocketing. Then he remembered. He sat up in horror and found while he had slept darkness had fallen. His teammates had set up a small camp stove. The hot smell of coffee and the wavery haze of smoke filled the stale, moist air trapped in the shelter with them. In its dim, flickering light, he could see the grim faces of his friends and knew they, too, had heard the rain hitting the canvas. Moving caused an onrush of pain to wash over him, and Sam answered his startled cry with more painkillers, antibiotics, and a swig of water. He took them all gratefully.

"How long?" he asked her quietly.

"Six hours...and I don't think the rain has let up at all. And now the wind is picking up again. So far the canvas seems to be holding, but..." Her report drew to an end, and he nodded his understanding. Things weren't looking up for SG-1.

"Promise the next time we see green sky, we hightail it home," he told her.

"I promise," she answered with a small smile.

Jack caught the glint of her smile in the stove light. Ahh, then things weren't so bad yet. It was when Carter lost her grin that he needed to worry. It took a lot to knock down her natural-born optimism. She was also way smarter than he was, and as a consequence always a step or two ahead of him in the 'what's coming-up' scenario-unless, like earlier today, she'd let herself get caught up in the wonder of discovery. Add to that, she was a lousy liar; it was easy to see when her smile was put on just to give reassurance. This one might be small, but it was real. She hadn't written them off yet, and he was glad to know it.

Because, frankly, the sound of the wind blowing the rain onto the sides of their shelter was enough to give him the willies without the patter of rain dripping onto the canvas over their heads. He figured it was only a matter of time before the acid or whatever was pouring out of the skies ate through its thick material and started on them. And then too, he'd taken a peek at Daniel's hand only a short time before...it was purple, swollen, and weepy. He didn't like the look of it at all. He didn't relish what they'd be forced to do if it continued to worsen and the damage began to look like it was moving up his arm.

He unfolded himself from the ground and walked the perimeter of their shelter one more time looking for any signs the rain was beginning to seep in under the canvas walls. So far that at least didn't look to be a problem. He poured himself another cup of coffee and contemplated what side of their shelter would be the safest to take a leak behind...he should have thought ahead and left a bit of room between the doubled layers of fabric they'd erected. You'd think after years of working with a female on the team, he would have it figured out by now. Then again, knowing Carter, she probably had thought ahead, and he could safely bet the south side of the shelter where she'd stretched the canvas had just what he was looking for. It did. He smiled his thanks at her when he ducked back in moments later. She nodded, but he didn't get a smile in return.

"What?" he asked sliding down next to where she sat near Daniel. Daniel's eyes blinked at hearing his voice, but it was clear the meds were pulling him back under. O'Neill gave him a small, reassuring pat on the arm as he settled into a more comfortable position.

She bit her lip and shook her head before answering, "There's no telling how long this storm is going to last...or how long the ground will be caustic after it stops."

"You're saying we may not be able to safely walk out of here even when it dries up?" he asked grimly.

"Yes, Sir," she answered. "Our boots conceivably might be as resistant as the canvas, but in time..." He nodded. "How was the outer wall?" she asked him.

"Good," he answered shortly and wondered if she could read his lies as easily as he could hers. He'd noticed several, small, smoking holes in it, but he couldn't see what good it would do her to know that.

Sam let his answer pass though it was obviously a lie. He was able to bluff his way out of a hole better than anyone she'd ever known when it came to dealing with an enemy, but he was a lousy liar when it came to friends. She thought he'd probably gotten away with unimaginable mischief at school but never quite managed to pull the wool over his own parents' eyes. It was the half-squint that gave him away. And, of course, quite often he couldn't hold back the smallest little shrug as though he'd apologize for the deception if he could.

She blew out a frustrated breath of air. They really needed a way out of here and fast. But, she was out of ideas. Before the night had fallen, she'd managed to get him to let her collect a bit of the moisture and discovered the rain's destructive element was basic instead of acidic. From there, it had been easy enough to render her small sample harmless with a couple of the vitamin C capsules Daniel carried. But, she doubted all the orange juice in Florida would be enough to neutralize an entire storm. And they were a long way from Florida.

The colonel sidled closer to her and slipped his arm around her. Quite on its own accord, her head rested against his shoulder. She'd stopped worrying what moments like this meant or what their teammates thought of them. If they were going to bring them official reprimands or raise questions of impropriety, then too bad. They were waiting for either the rain to stop falling so they could get on with their work or a particularly unpleasant end...what could it hurt if they waited together?

"What do you think, Carter?" he asked after awhile, "Is it letting up a bit?"

"I don't think so, Sir," she told him though she knew it wasn't what he wanted to hear.

"That's what I thought, too," he told her sheepishly, "but I was hoping."

"Yes, Sir," she answered him. She idly wondered how many 'Yes, Sirs' she'd said in her career, and if she'd been in the Air Force long enough that they now outweighed all the ones she'd spoken growing up the daughter of an Air Force officer. Anything to keep from thinking about looming eventualities.

She wondered if the inappropriateness of her thoughts had somehow transmitted themselves to him when he asked, "What are you thinking?"

"Not much, Sir," she answered, but he cocked his head at her to tell her that wasn't go to work. "Actually, I was just thinking about how many times I've said 'Yes, Sir' in my lifetime."

"Ahh," he answered. "The 'yes, sir' equation."

"Yes, Sir," she said quietly laughing against him.

"I've said my share," he said, "but I'm pretty sure you work more in than anyone else I know. Yes, Sir, I'd say you're the champion yessirer." His tone was still playful, but she thought she heard something behind it. She chanced a glance at his face and wondered if he was thinking the same thing she was. That she'd said 'yes, Sir' one time too many under the surface of a planet they'd all rather forget. They'd walked into a room not knowing who and what they were and left all too aware of the rules and regulations that made her 'yes, sir' necessary. It had signaled the end of shared nights and comfortable togetherness, and he'd repeated the word 'sir' back to her as though it was the ultimate dirty word. As though it ate into him like the caustic rain was eating through the canvas sides of their shelter.

"There wasn't anything else we could have done, you know?" he said, telling her that they were thinking the same thing.

"Maybe," she said quietly. "Sometimes I wonder." Sometimes, she hated herself for being so willing to utter that 'yes, Sir' and let what they'd been developing between them slip away like the false memories with which they'd been implanted. Sometimes, she thought what was always hovering between them was worth fighting for, and she was a fool to not tell him so.

"Do you?" he asked.

"You don't?" she answered back.

"No," he said quietly and with certainty, but she felt the small shrug of his shoulder against her back and glanced up to see his eyes half-screwed up in a squint.

He scowled at her questioning look and hoped she couldn't read the lie in his face. He asked himself every day and twice on Sundays why he didn't just hand in his resignation and take her home, or, at least, swallow his pride and beg her to resign her commission. The Air Force wouldn't like it. He'd never see a star on his uniform, but they'd keep her on in a civilian capacity-she was too valuable to the program to do otherwise. But, he'd promised himself he'd never ask her to do that.

And the other was unthinkable. Without his commission, what did he have to offer the program? Not one thing. He'd be out of the fight. He was-they were-Air Force officers in the midst of the worst conflict Earth had ever faced. They couldn't just walk away from their duty because they'd had the unbelievably bad judgment of falling hopelessly in love with a fellow officer.

He shifted uncomfortably beside her. "No, we were right," he asserted. "There's too much at stake...Earth, freedom, the whole song and dance. We've got jobs to do and we can't let...feelings get in the way of doing them."

"Yes, Sir," she said looking away so she didn't have to see him wince at her choice of words. He glanced at Daniel, still zonked on the meds, and Teal'c, studiously studying the canvas walls and avoiding looking their way. He'd spoken to Teal'c about the situation, warrior to warrior. The Jaffa had given up his own wife and son to fight against the Goa'uld...what could he advise him, but that the sacrifice must be made and it was a worthy one?

He'd talked, ok, hinted actually, at Daniel about it, too. Daniel, who'd lost his wife to the Goa'uld, had told him in not so many words to stop being a fool and marry her already. Life held too many uncertainties to not grab the chance at happiness while he could. All in all, their conflicting advice had been no help.

The 'hypothetical' conversation he'd had with Hammond had given him no clearer picture, and Siler, the wise, old man on the base, had been worse than useless. He'd refused to give him any words of wisdom at all on the grounds it wasn't his place. He was right, of course, but he couldn't very well discuss it with the one person whose place it was to have an opinion. Not without risking the delicate, tightrope act he carried out with her on a daily basis. These quiet, almost-conversations were the closest either of them dared to discuss a subject he guessed was uppermost in both of their minds a good portion of every day.

They sat without speaking as the greenish light of the morning filtered through the leaves and canvas over their heads, and the rain finally faded off into the distance. She slipped out from under his arm to find her way into the little space she'd made in the south wall, and he stretched and wondered along the walls checking once more for leaks. Daniel stirred in his sleep and turned over. He could see that the hand, though still swollen, discolored, and weepy, looked no worse than it had the last time he'd checked it.

He nodded at Teal'c and they pulled back a bit of the canvas to see a spectacular, though rather disconcerting, yellowish-green sunrise through the trees. Under its light, the few remaining clouds lightened to the color of spring grass, and he optimistically guessed the path would dry and be perfectly safe for them to follow within the next few hours. He grunted in satisfaction.

They'd make the last of their journey to check for tritanium and doubtlessly find the mother lode. Along the way, their own brilliant Samantha Carter would figure out a way to protect the miners who were sure to follow them from the caustic rain. It would be another successful mission for the record books, he was sure of it. They were SG-1 after all...and if they sacrificed to remain a team, it was only fair that occasionally things worked out for them in return.

 _Author's Note: When I first posted this, I received the following comment:_ ok, but there is no such thing as tritanium, i suppose you meant trinium.

 _To be clear, I strive to be true to the characters and stick to canon when the story allows it. Full Stop. As for the rest, I do like to be at least superficially realistic-sounding in my background settings and such, but I never imagined anyone would expect my 'science' to hold up to the light of day. Truthfully, I thought I did well enough in that regard that I was a bit miffed the reader just assumed I hadn't bothered to get the show's fictional element right instead of considering that maybe I'd made up an element of my own. (Oi! the life of a scifi fanfic writer!). Still, I wanted to be gracious in my response and ended up having a bit of fun with it so am sharing it here:_ Nope. Though their names may have a superficial similarity, they are entirely different elements. Like trinium, you won't find tritanium on the table of elements you and I learned in our high school chemistry classes, because, like most things the SG teams have discovered offworld, it is classified and top secret. It is worth more than our lives for me to obtain a copy of the appended periodic table that includes the elements found only offworld so you will simply have to take my word for it, but tritanium is just as real as trinium!

Thanks for reading and lol, Offworlder-a writer (or at least a dabbler) of science FICTION


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